1. Field of Invention
The present invention relates to impact absorbing devices, particularly to energy absorbing impact systems for vehicle bumpers and the likes.
2. Description of the Prior Art
Examples of energy absorption units in bumper systems can be found in U.S. Pat. Nos. 6,406,081, 7,066,509, 7,131,674 and 7,192,067. They disclose structures to convert impact energy into bumper deformation.
U.S. Pat. No. 6,942,261 discloses a linear actuator dampening the motion of a piston by forcing a high viscosity liquid to flow through constricted openings. As the piston slides towards the constricted openings, the kinetic energy of the liquid transforms into heat energy.
None of those patents consider optimization by providing constant deceleration and as a result, minimization of forces applied to the passenger cabin and the people in it.
A need still exists for energy absorption systems that minimize forces applied to passengers and can absorb large amounts of energy with predictable energy absorption characteristics. They have to be compact, lightweight, inexpensive, and incorporate a relatively simple design.